Sunning by Black Noddies (Anous minutus) May Kill Chewing Lice (Quadraceps hopkinsi)

Abstract

spite decades of interest in this behavior, however, no one has tested the hypothesis that sunning adversely affects ectoparasites (Blem and Blem 1993).We demonstrate experimentally that conditions experienced during normal sunning are lethal to chewing lice, which is consistent with the ectoparasitecontrol explanation of sunning.Methods.--We studied the sunning behavior of Black Noddies (A nous minutus) at the Heron Island Research Station (HIRS; 2326'S, 15155'E) on the Great Barrier Reef of Australia.At this location, Black Noddies sun gregariously on bare sand and on the roof tops of HIRS buildings.From 30 October through 2 November 1991, we investigated the relationship between sunning activity and temperatures at the sunning site.The typical sunning posture used by Black Noddies is a standing position with tail fanned and one wing extended (Fig. 1).To estimate the thermal environment experienced by a Black Noddy wing during sunning, we mounted thermometers about 6 cm above each of three sunning sites.The thermometers were exposed to the sun and mounted so they could be read from a distance with a spotting scope.The number of sunning noddies and the temperature at each site were noted periodically over two days.Any noddy that alighted on the exposed sunning sites was considered to be sunning.The longest time we observed any individual sunning